Characterization of Si-rich a-Si1−xNx:H alloys deposited by laser-CVD

Abstract Highly silicon-rich amorphous hydrogenated silicon nitride (a-Si 1− x N x :H) alloys (0.11 x −1 whose dependencies on the substrate temperature (200–400°C) and the percentage of disilane in the gas mixture are presented. While the growth rate increases exponentially with the temperature, its variation with the decreasing disilane content shows an initial decrease followed by sharp increase at a critical precursor gas composition and subsequent decrease for gas mixtures having very low disilane content. Films have been analysed by Fourier transform infrared spectroscopy (FTIR), energy dispersive spectroscopy (EDS), profilometry and UV spectroscopy. The band gap measurements reveal that these silicon-rich films with compositions below the percolation threshold of Si–Si bonds (i.e., x